Telephone system.



J. ERKCKSON.

TELEPHONE SYSTEM,

APPLICATEON FILED MAY 22. I916..

1,209,826. Patented Dec. 26,1916.

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fnzrsnfur HIKE nai J. ERICKSON.

TELEPHONE SYSTEM.

APPLICATION FILED MAY 22. 1915.

i i @Qfiffi. Patented Dec. 26,1916.

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BESTAVAILABLE COP l. EFHCKSON.

TELEPHONE SYSTEM.

APPUCA HON FILED MAY 22.19i6. [$09,826. Patented Dec. 26,1916.

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TELEPHONE SYSTEM.

APPLICATION mm MAY22.19I6.

Pas-wilted Des. 26, 1916.

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], ERICKSON.

TELEPHONE SYSTEM.

APPLICATION man MAY 22. 1915.

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UNITED STATES PATENT OFFICE.

JOHN ERICKSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION or rumors.

Specification of Letters Patent.

Patented Dec. 26, 1916.

Original application filed December 18, 1908, Serial No. 877,266.. Divided and this application filed May 22,

. 1916. serial No. 99,108.

To all whom it may concern Be it. known that I, JOHN citizen of the United States and resident of Chicago, Cook county, Illinois, have'invented a certain new and useful Improvement in Telephone Systems, of which the following'is a specification.

My invention relates to automatic or semiautomatic telephone exchange systems in general, but more particularly to those in which the substations are provided with rotary calling dials, and especially to systoms in which thesaid dials are used for controlling the operations of switchesthat have one motion to select groups and another motion to connect with a line in any selected group, as, for example, selectors that have one motion to select groups or divisions of the exchange and another motion to automatically select an idle trunk line in the group or division selected by the calling subscriben'or a connector that operates in the same manner, except that its second motion is inder the control of the calling subscriber to seize or find the called line.

An object of my invention, broadly speaking, is to provide an improved arrangement whereby the dial cannot be forced or so manipulated as to accelerate the impulsetransmitting mechanism, and which will make the proper transmission of the impulses a matter of greater certainty, especially in cases where the subscribers are inclined to be careless about the Way in which they use the calling dials.

More specifically considered, an object of my invention is to provide a calling dial which can only rotate in one direction, and which is operatively connected with the impulse-transmitting mechanism, whereby the dial cannot be forcibly turned backward to unduly accelerate the transmission of electrical impulses. Another object is to .provide a measuredservice system of such character that the calling subscriber is required, by means of improved mechanism, to remove a Sl10It-C1Y-- 'cuit or shunt from around his transnfitter, and to thereby register the call, before he can converse with the called subscriber.

To these and other useful ends my inven- 1 (Fig.9) is pivotally secured tothe link 20 at the point 21; and'the link 20, which-is {tion consists in mid claimed.

matters hereinafter set forth ERIOKSON, a of America,

In the accompanying drawings Figure 1 is a front. elevation of the keyboard, showing the rotary dial. Fig. 2 is a rear elevation of the keyboard. Fig. 3 is a side view thereof as seen from the right in Fig. 1. F ig. 4: is a cross-section on line 4-4 in Fig. 2. Figs. 5, 6, 7, 8, 9, 10, 11, 13,14,15 and 16 are detail views of the keyboard mechanism. Fig. 12 shows a switch-hook spring combination. Fig. 17 is a diagram of thesubstation A comprising a keyboard of the character shown in the preceding figures. Said substation i's connected with automatic switching apparatus in a central ofiice, said apparatus being ofv the character designed to be operated by the said keyboard, the said switchingappar tus, as shown, comprising a line switch C, a controlling master switch D and a first-selector E, and there being a central battery B for supplying all operatis secured to the hub 8, but the hub in turn is loosely mounted upon the shaft 7, so that the dial may be turned Without rotating the shaft. One end of a coil spring 9 engages a'slot 10 in the hub S (Fig. 8). The other end of thisspring is secured to the spring box 11, to which latter is also fastened the impulse Wheel ratchet 12. The members 11 and 12 are firmly secured to the shaft 7, and hence when the ratchet Wheel 11 is turned the shaft and all the parts secured thereto are rotated. Also fastened to the :dial on the inner side is the dial ratchet wheel 13. The gear Wheel 1,.together with the impulsetransmitting Wheel 14, are secured to the hub 15, and the hub 15 in turn is rigidly fastened to the shaft 7 by a screw clamp 16. The shaft 7, carrying all-the parts secured thereto, is adapted to rotate in bearings in the front and back plates 17 and 18. The pawl 19, which jzontrols the ratchet Wheel 13 provided with the. arm 22. is pivotallv mounted on the front plate 1? at the point 23. The special spring it provides the ten- .-ion for the pawl 19 and arm 22. The lever which is pivoted at the point 26, is arranged to normally engage the ratchet 12 when the dial turned l'oiwvard.

In Fig. i) the parts are shown in their normal relative positions. the dial and ratchet wheel being at rest.

In Fig. 10 there are shown the positions these same parts assume when the dial, to which is secured the ratchet wheel 13, is turned in the direction indicated by the ar row. tween the dial and ratchet wheel 13 with the wheel 12-, there is a tendency for this latfor wheel to follow in the direction of the dial. but this is not permitted by the lever at this time.

In Fig. 11 there are shown the relative positions these parts assume when the dial is released. \Vhen the dial is released the wheel 13. which is rigid with the dial, due

' to the tension placed on the spring 9 (Fig.

4), tends to rotate in a dlrection opposite to V that indicated in Fig. 10. A tooth 27, however. immediately engaged the pawl 19 and carries the latter backa trifle, thereby moving the pawl 19 and link 20 against the tension of the spring 21- about the point 23. When this occurs the arm 22 presses against the outside lip of the lever 25, thereby carr ving the latter out of engagement with the ratchet wheel 12. The Wheel 12 and shaft 7 then respond to the tension in the coil spring 9 (Ifig. 4) and move in the direction indicated by the arrow in Fig. 11. The dial ratchet wheel 13 remains locked at this time. Upon the other end of the shaft 7 (as shown in Fig. 4) is mounted the impulse wheel 14. and gear wheel at, as explained. The impulse wheel 11, in turning counter-clockwise Figs. 15 and 16), presses against the spring 28, thus separating the impulse springs 29 and 30 each time a tooth passes the spring 28.

f t the dial is turned, as explained,

the stop screw 31 upon the wheel 13 (Fig.

6) is carried away from the member 32, and

when the dial is released the shaft 7 and all the parts secured thereto follow or rotate in the same direction as the dial until the member 32 reaches the stop screw 31 (Fig.

.7). The distance or are that the stop screw advances from the member 32 and definitely determined by the finger-holes in the dial. Therefore, when the dial is turned for the digit 5 the stop screw 31 is advanced through an are such that the member 32, in coming to normal position again, permits the impulse wheel 14 (Fig. 15)

is accurately to break the normal contact between the springs 29 and wheel 41 engages 3, which latter five times. The gear the pinion of the governor controls the rapidity with Since there is springconnection be-v which impulses are, transu'iitted. In Figs. 13 and 11 it will be seen that there are two notches or positions in the lever 33 for the end of the switch-hook This provision is made in order that certain telephone circuits may be controlled through the switch-hook springs. \Vhen the receiver is removed from the switch-hook the end of the latter occupies the position shown in Fig. 13, and when the dial comes to rest after a digit has been called the switch hook rests in the position shown in Fig. 11. This operation is brought about as follows: \Vhen the receiver is removed the end of the,switch-hook rests in the notch 3%. Normally, however, before. the receiver is removed, the switch-hook rests against the stop 35. After the dial is turned and then comes to'rest, the pawl mechanism, as explained, presses the lever out of engagement with the ratchet wheel 12. Also, when this happens the finger 36 upon the lever presses the lever 33 outwardly a trifle (Figs. 11, 13 and 14). thereby permitting the switch-hook to t'all to I the notch 37.

In the foregoing the mechanical construction and arrangement of the different parts of my calling device have been explained. It will now be pointed out how the calling device may be used in connection with a subscribers telephone for operating the switches of an automatic central oilice. As shown in Fig. 17, the substation A comprises, in addition to the calling device, the receiver 38, ringer 29 in series with the condenser 40, an induction coil 41 comprising the primary winding 4'2 and secondary winding 43, and a transmitter 44.

In Figs. 12 and 17 the switch-hook spring combination is arrangcd'for the operation of a meter or registering device at the telephone. It the meter or registering device is not used, then the two lower springs 54 and 55 are not used, and the switch-hook spring combination is thesame as shown'in Figs. 1, 2 and 3. In addition there is shown a meter or registering mechanism consisting type of line switch disclosed in English Patout No. 26,301 of 1906, and in the W csiern Electrician published at Chicago, Illinois, U. S. 11., January 25, 1908. The controlling master switch D is also distzloscd in the above references. The selector switch E is ofthe general type of selector switch shown in UnitedStates Letters Patent No. 815,321, issued to Keith, Erickson & Erickson March .13, 1906. As shown in Fig. 17, all of the switchcs'and the telephone A are wired with circuits such that they will operate on a twowire system--that is, there is no operating 1 ground at the subscribers station, the 1m- Y tral office only.

- switch through the tripmagnet 59, bridgecut-off springs 60 and 61 to the line con pulses being made by opening and closing the two l1ne conductors in series, so that the ground connectlons are employed at the cenductor through the primary Winding 42, transmitter 44, springs 55 and 54, impulse 4 springs 29 and 30 to the conductor 52,

bridge-cut-ofi? springs 62 and 63, resistance coil 64 to the battery lead 65, thence through battery B t groundG. The trip magnet 59, upon energizing, attracts its armature and permits the plunger to engage an idle bank terminal, thereby pressing the springs 66 and 67, 68and 69,70 and 71, and '72 and 73 into contact. The engagement of the springs 70 and 71 establishes an energizing circuit through the bridge-cutsoif relay 74 which operates to disconnect the line conductors 52 and 53 from the line switch connections. Also, when the springs 70 and 71 engage, then a positive guarding potential'is established over the conductor 75 at the connector private bank contact corresponding to the line of substation A. The engagement of the bank spring 68 and 69 closes an energizing circuit through the motor magnet re- I lay 76 of the master switch D. This circuit extends from ground Gr through the'winding 77 to the common segment 78 of the master switch bank wiper 79,- to the individual contact 80 (assuming that this contact corresponds to the bank terminal just engaged by the line switch C), conductor 90, back .springs 69 and 68, winding of the release magnet 91 to the battery lead 65, thence through battery B to ground G. Although this circuit includes the windings of the release magnet, the said magnet-does not open ati vel y energize, since the winding 77 of'the relay 76 is of suchcomparatii elyhigh. resistance that a very small current is flowing.

The relay 76, upon energizing, presses the springs 92 and 93 into contact, thereby closing an energizing circuit through the motor magnet 94 extending from ground Gr lVhen the subscriber 'removes the receiver 38 from the switch-hook through the springs 92 and 93,- interrupter spring 95, motor magnet 94 to the cattery 'lead 65, thence through battery B to ground G. The motor magnet energizes and operates the ratchet wheel 96 one step, assuming the next trunk line is idle, whereby the shaft 97 carries the idle plungers opposite the next idle bank terminal and the wiper 7 9 into engagement with the individual contact corresponding to the idle trunk. The engagement of the bank springs 66 and 67 and 72 100 extending from ground Gr through the winding 101, side switch Wiper 102, conductors 99 and 53, through the substation to the conductors 52 and 98, side switch wiper 103, winding 104 to the battery lead 65, thence through battery B to ground G.. This line. relay energizes and separates the spring 105' from the spring 106, and closes the springs 105 and 107 in contact. The engagement of the latter springs closes an energizing circult through the slow-actingrelease relay 108which operates to in turn carry the spring 109 out of engagement with the spring 110 and into engagement with the spring 111. This line relay 100 remains in this energized positionas long as the line 'at the substation is closed, but when the dial is ro tate'd, and in turn the impulse wheel 14, the impulse springs 29 and 30 are then separated momentarily, .thereby intermittently breaking the energizing circuit of the line relay 100. The denergizing of the line relay 100 permits the spring 105 to engage the spring 106, thus closing a circuit through the Vertical magnet 112. This circuit extends from ground G through the springs 105 and 106, springs 109 and 111, private magnet relay 113, vertical magnet 112, side switch wiper 114 to the battery lead 65,-

thence through batteiyB to ground G. The

vertical magnet energizes and operates to carry the shaft wipers 115, 116 and 117, in a vertical direction-one step at a time for each impulse. Since the vertical magnet circuit relay 113 restores to normal position, breaking the energizing circuit for the private magnet 120 which operatesto pass the side switch to second position. The side switch wiper 114, upon passing to second positip'n,

BEST AVAILABLE COP 4:

closes an energizing circuit through the rotary magnet 121 which operates in the usual manner to carry the shaft wipers in a rotary or circular direction and into engagement with the bank contacts of an idle trunk line leading to the next succeeding switch. Furthermore. when the switch shaft. given a vertical step the normal arm 122 permits the spring 123 to engage the contact point 12% thereby connecting the main battery lead with one terminal of the release magnet 125. When the side switch wipers 103 and 102 pass to third position the line conductors 52 and 53 are extende to the shaft wipers 115 and 11a. respectively. and to the trunk conductors 12c and 1'27, thereby closing an energizing circuit through the line relay 1% of the switch l in the same manner in which the circuit was closed through the line relay 101') of the switch The calling subscriber may operate the line relay 128 of the switch F in accordance with the next digit of the desired number. After having ope 'ated the dial for each digit. and established connection with the desired. line, the two subscribmay carry on communication. The subscriber at substation A. however. bct'orehe :an successfully talk with the called party, must: press the. button 13. thereby separating the springs 46 and t and operating the meter one step. as explained. It will be seen that before the meter button pressed there is a. shunta round the transmitter l l: through the springs 58 and 57 to the spring The calling subscriber, moreover. may hear the called party answer. but before the calling subscriber can reply. the transmitter shunt must be removed by pressing the button which registers the call.

The meter mechanism, when once operated, remains in it operated position until the calling subscriber restores his receiver to the switch-hook and thereby unlocks the locking pawl fi The restoration of the central ollice switching apparatus occurs when the calling subscriber restores his receiver to the switch-hook and opens the energizing circuit for the line. relay oi the coniwctor switch. The line relay. upon deeneigizing. breaks the energizing circuit for the slow-acting release relay. which in turn also falls back, thereby removing the ground potential from the private bank contact engaged by the. private wiper 117. The rc moval of this ground also breaks the encrgizing circuit of the slo '-acting relay 108 of the selector I This relay then falls back. placing the spring 109 in contact with the spring 110. thereby closingan energizing circuit lhrough'the release magnet extending from ground (i through the springs 1.03 and 106. springs 10%) and 110. through the release magnet normal springs 1% and 123 to the battery lead 65. thence through battery B to ground G. The

release magnet, upon energizing, restores the switch shaft and side switch to normal position. llhcn the switch shaft reaches normal position the normal arm 122- upon the shal't carries the normal springs 123 and l2lout of engagement. thereby breaking the. energizing circuit for the release magnet. The release magnet, when energizcd. holds the springs 12$) and 130 in contact. thus closing the energizing circuit for the release magnet i of the line switch 0. The release magnet ill energizes and open ates the release mechanism to withdraw the plunger from the bank terminal and pen mit the bank springs to restore to normal position. At the subscribefis station, when the receiver restored. the switch hook springs return to normal position; also. the rod 51 presses the pawl. 0 so that the meter button springs return to normal position.

From the foregoing it will be seen that there is no normal position for the dial and the impulse 'vhccl that is. the dial is rotated in one direction only, also the impulse wheel. When the dial is turned for any number, tension is placed in the dial coil spring. This tension is transmitted to the shatt. but the shat't prevented from turni g intil the dial mines to rest, when a. lo- H. which holds the shaft locked is removed. The shaft being tree then responds to the spring tension and rotates in the same direc tion that the dial was previously turned. The number of impulses transmitted is determined by the are through which the dial is turued-that the impulse wheehiiyrespouse. to the spring tension of the dial springs. rotates through an equal arc. will be seen that the switch-hook 5 is permitted to pass tron: the position shown in Fig. 13 to the position shown in Fig'f-l-t by the action of the lever This lever 2.). by being pressed away from the gear 12. as shown in Fig. ll. through the medium of the pin Ill). presses the catch 33 away from the swit h-hook 5. thus permitting the add switch-hook to pass lrom one position to tilt other.

ln the foregoing reference has been made to connector switches. It should therefore, be stated that connector switches with which the selector l) is adapted to establish connection tor completing the circuit between the calling and called subscribers are of the general type. disclosed in United States Letters Patent-No. 815.176. issued March 13, 1006, to Keith. Erickson & Erickson. More particula rly, however. Lib; connector switches in this system are adapted to the particular character of system and circuits herein disclosed.

It will be seen that 1' provide a rotary impulse wheel and a. rotary calling dial operatively connected. together in 'such a manner that thedial rotates fir t and the impulse wheel afterward, the rotation of the wheel always being coextensive with and determined by the rotation of the dial. The dial is rotated for the difierentdigits of the called number, and at the end of each rotaalways corresponds in degree to the rotation of the dial. The dial rotates ahead, drawing away from the wheel, so to speak, but as soon as it stops the wheel is then released and allowed to catch up and regain its normal position relativeto the dial. Thus the dial and the wheel rotate always in the same direction, the dial rotating first and the wheel afterward, the release of the wheel being efi'ected by a very slightback rotation of the dial. Obviously, however, the dial is never rotated backward to an extent to bring it to its normal position. In view of its continuous rotation always in the same direction the dial is, therefore, provided with an endless series of finger-holes adapted to be used in the manner described.

It will also be seen that the calling subscriber, after establishing connection through the automatic apparatus to the called line, cannot then converse with the .called subscriber until after he has removed a short-circuit or shunt from around his transmitter. When the calling subscriber does this he at the same time registers the call, or collects the coin or check. For the broader purpose of my invention the measured, service device may be of any suitable character-that is to say, it may be a coin or check controlled mechanism or a callregistering device of any suitable, known or approved character. Whatever it may be, however, the use of the calling subscribers transmitter to converse with the called subscriber is contingent upon the operation of such device.

hat I claim as my invention is:

1. In a common battery telephone system, a subscribefls station having-a circuit including a talking transmitter and an impulse transmitter in series, means for shunting the talking transmitter, and means for operating the said impulse transmitter, to-

gether with a line terminating at one end' in said telephone and at the other end in an automatic switch responsive to the impulses of said impulse transmitter.

4 2. In a common battery telephone system, a subscribers station having a circuit including a talking transmitter and an imulse transmitter in series, means for shunt- T ing the talking transmitter. said means controlled by the impulse transmitter, and means for operating the said impulse trans mitter, together witha line terminating at one end in said subscribers station and at the other end in an automatic switch responsive to the impulses of said impulse transmitter. Y i

3. In a common battery telephone system, a subscribers station having a circuit including a. talking transmitter and an impulse transmitter in series, a circuit for shunting the talking transmitter, said circuit controlled by the impulse transmitter, and means for operating said impulse transmitter, together with a line terminating at oneend in said subscribers station and at the other end in an automatic switch responsive to the impulses of said impulse transmitt .r.

4,111 a common battery telephone system, a subscribers station having a circuit including a talking transmitter and an impulse transmitter in series, a push button at the subscribers station, a circuit for shunting the talking transmitter, said circuit controlled by both the impulse transmitter and the subscribers push button, and means for operating said impulse transmitter, together with a line terminating at one end in said subscribers station and at the other 'end in an automatic switch responsive to the impulses of said impulse transmitter.

5. In a common battery telephone system, a subscribers station having a circuit including a talking transmitter and an impulse transmitter in series, a push button at the subscribers station, a circuit for sl1unting the talking transmitter, said circuit controlled by the subscribers push button, means for operating said ter, together with a line terminating at one end in said subscribers station and at the other end in an automatic switch responsive to the impulses. of said impulse transmitter.

6. In a common battery telephone system, a subscribers station having a circuit including a talking transmitter and an impulse transmitter in series, a push button at the subscribers station, a circuit for shunting the talking transmitter, means for closing said circuit when said impulse transmitter is operated, means for opening said circuit when said pun button is operated, and

impulse transmitmeans for operating said impulse transmitcircuit for shunting the talking transmitter, said circuit controlled by both the BEST AVAILABLE COP impulse t 'ansmitter and the manually operated mechanism, and means for operating said impulse transmitter, together with a line terminating at one end in said subthe remaining portion of the distance, and

a circuit controlled by said switch hook in its last movement.

9. In a. telephone substation apparatus, the combination with a switchhook, a receiver and a transmitter, said switch hook movable a. definite distance, of means for limiting the movement of said switch hook to a portion of said distance when the receiver is removed from said switch hook, means for thereafter permitting the switch hook to move the remaining portion of the distance, said transmitter controlled by said switch hook in its last movement.

10. In a telephone substation apparatus, the combination with a switch book, a receiver and a transmitter, said switch hook movable a definite distance, of means for limiting the movement of said switch hook to a portion of said distance when the receiver is removed from said switch hook, means for thereafter permitting the switch hook to move the remaining portion of the distance, and a shunt for said transmitter controlled by said switch hook in its last movement.

11. In a telephone system, a substation apparatus comprising; a switch hook and a receiver, said switch hook movabl* a. definite distance, means for limiting: the movement of said switch hook to a portion of said distance when the receiver removed therefrom, and for thereafter i'iermitting said switch hook to move the remaining portion of said distance.

12. In a telephone system, a substation apparatus comprising a switch hook and a receiver, said switch hook movable a definite distance, means for permitting said switch hook to move a portion ot said distance when the receiver is removed therefrom, said means being thereafter operated to permit said switch hook to move through the remaining portion of its distance.

13. in a telephone svstem, a substation apparatus comprising a switch book. a receiver, and a transmiitcr. said switch hook movable a definite distaimc. means tor permittin e said switch book to move a portion of said distan when the recei r is remo ed therefrom. said means being; thereafter opcrau to permit said switch hook to move throw the remaining portion of its distance, transmitter controlled by said switch h ok in the last movement.

H. 111 a common battery telephone sjvstw a snbscribers station having a circuit in cluding a talking transmitter and an impulse transmitter in series, means for shunting the talking transmitter while the impulse transmitter is operated, and means vi'or operating said impulse transmitter; together with a line terminating. at one end in said telephone. and at the other end in an automatic switch responsive to the impulses in said impulse transmitter,

15. In a common battery telephone trunking system, a calling subscribers transmitter, a line circuit "for supplying the same with current for talking purposes, means for establishing a trunking connection between a calling and a called subscribers line. means under the. control otthe calling subscriber and operative to open he line circuit for releasing said trunking cl alncction to the called subscriber, a short-cir uit around the transmitter, and a measured service device reqnirin g actuation thereof to remove the short-circuit from around the transmitter before the calling subscriber can converse wizb the called subscriber.

16. In a telephone trunking system, a

s11 scribers line. a measured service device associated therewith, a transmitter and an impulsctransmittin;, device at the substation thereof, a central station switch responsive to said impulse-transmitting device to extend the call in the direction. 01' the called subscriber, means under the control of the calling subscriber and operative to open the line circuit for releasing said trunking con nection, means for supplying current to the line for talking and calling purposes, a short circuit for said transmitter controlled by said measured service device, means for operating said measured service device and for removing said short circuit from said transmitter.

1.7. In a telephone trunking" system, a subscribers telephone and line therefor, means including, an automatic trunking switch for establishing a trunking connection between a. calling and a called subscribefs line, a subscribers impulse-transmitting device for controlling said automatic switch, means under the control of the calling subscriber and oDerative to open the line circu't tor releasing trunking connection to the called subscriber. a measured service device associated with said subscribers telephone means controlled thercb for controllilng the operation of the telephone and for a sessing toll t all successful calls from said line, and means for supplying current to the line for takine' purposes.

llltl 18. In a telephone t runking system, an automatic switch at the central station, a subscribers telephone and line therefor, means "for controlling said switch over the two sides of the line in series to extend the call in the direction of the called subscriber, means under the control of the calling subscriber and operative to open the line circuit for releasing said trunking connection, and a measured service device associated with 10 and controlling the operation of said telephone and for assessing toll for all successful calls from said line.

Signed by me at Chicago, Cook county, Illinois, this 16th day of May, 1916.

JOHN ERIGKSON. 

